Will be starting with the harness I have done 15 or more harness and have it to a science I can either post just project pics or explain my every move!
If I had your truck and yes that 6 is a good engine but I would have it out of there so fast hell my father in law has been trying to sell me his straight 6 fully rebuilt engine that came out of his blazer for 12 years i say and in my opinion only find a v8 sbc parts rain from the sky just have...
Here are a couple more thing different between the 2
Spring pad is 2 1/2 in wide
The spring studs are smaller (chevy is 5/8 while dodge is 9/16)
The spring studs are closer together
The shock mounts are just visibly obvious
The driver side spring mount is cast iron while chevy is steel.